The outward appearance of a portable computing device can be important to a user of the portable computing device. Design, heft, ease of portability, and overall aesthetic appearance are factors that many users consider when choosing a portable computing device for personal use. At the same time, the assembly and overall functionality of the portable computing device are also important to the user, since a durable assembly can extend the overall life of the device and thus increase its value to the user. Various factors that can be considered in the design of portable computing device components can include weight, strength, durability, cosmetic appearance, manufacturability, and thermal compatibility, among others. A component that is selected on the basis of its positive contribution to one of these design factors can have an adverse impact on one or more other factors.
One design challenge associated with the manufacture of portable computing devices is the design of the outer enclosures used to house the various internal computing components. This design challenge generally arises from a number conflicting design goals that include the desirability of making the outer enclosure or housing lighter and thinner, of making the enclosure stronger, and of making the enclosure aesthetically pleasing, among other possible goals. Lighter housings or enclosures tend to be more flexible and therefore have a greater propensity to buckle and bow, while stronger and more rigid enclosures tend to be thicker and carry more weight. Unfortunately, increased weight may lead to user dissatisfaction with respect to clunkiness or reduced portability, while bowing may damage internal parts or lead to other failures. Further, few consumers desire to own or use a device that is perceived to be ugly or unsightly. Due to such considerations, portable computing device enclosure materials are typically selected to provide sufficient structural rigidity while also meeting weight constraints, with any aesthetic appeal being worked into materials that meet these initial criteria.
As such, outer enclosures or housings for portable computing devices are often made from aluminum, steel and other inexpensive yet sturdy metals having a suitable thickness to achieve both goals of low weight and high structural rigidity. The use of metal enclosures is also convenient from the standpoint of providing a ready electrical ground and/or a ready radio frequency (“RF”) or electromagnetic interference (“EMI”) shield for the processor and other electrical components of the computing device, since a metal enclosure or outer housing can readily be used for such functions. In the event that alternative materials might be desired for such outer housings, however, such as for alternative aesthetic appearances and/or lighter overall devices, then various complexities may arise with respect to the traditional grounding and/or EMI shielding functions traditionally provided by a metal enclosure.
Further electrical issues may also require consideration where a traditional metallic outer housing or enclosure is not used for a laptop, netbook, tablet, or other portable computing device. For example, any desired RF transmissions to or from the portable computing device may require alternative antenna considerations, as well as additional electromagnetic or electrical shielding with respect to any processing components in the same device. In addition to raising various potential electrical issues, the use of a non-metallic or otherwise non-conducting outer housing or enclosure for a portable computing device might also present alternative issues with respect to other components, such as, for example, audio systems, visual display presentations, and input and output ports, among others.
While many designs and techniques used to provide enclosures for portable computing devices have generally worked well in the past, there is always a desire to provide further designs and techniques for alternative aesthetically pleasing yet mechanically strong and lightweight portable computing device housings. In addition, there is an accompanying desire to provide any alternative schemes or structures that might be desirable due to any deviations from traditional portable computing device housings, such as with respect to overall electrical system, EMI or RF shielding and/or audio system considerations.